For the past six months or so I have had two tanks in the same room, with the same temperature and same water. Ok, strictly speaking one of them isn't actually a tank, it's a plastic storage crate that got co-opted into the aquascaping hobby. The room is bright and over the summer both tanks flourished. This is the storage crate back in July (both tanks have a mix of frogbit and water lettuce):
The storage crate had only natural lighting, and the tank has an actual light (Lominie LED Asta 120, 12 hours a day). Over the summer I was taking handfuls of floaters out of both tanks weekly. Then as the days shortened and the light got less intense, the storage crate has slowed down, and I last took frogbit from it in November. The frogbit itself looks a lot less happy. Meanwhile the tank continues to need thinning out weekly. Here they are in December:

I talked to my partner, who is a gardener and she reckoned that the frogbit was properly dying off due to lack of light. I've bunged a cheap light I had in the doodads drawer onto the crate and the frogbit immediately looked happier
Meanwhile upstairs I have a completely neglected 12L Marina which I threw some plants and shrimp in a year ago. It gets a WC about once a month, tap water only, and every now and then I remember to feed the shrimp in it. The frogbit in that makes all other frogbit look like fake feeble wannabe tadpolebit....

And yes the emersed plant you see there is Alternanthera Reineckii 'Mini', which according to Aquarium Gardens "...
displays compact and low growth, making it perfect for small aquariums". Ho ho ho. All I can say is I'm glad I didn't get the non-mini variant!
Talking of Aquarium Gardens, I was in there the other day being inspired and buying another tank (MTS - Aaaaargh) - the same day in fact that
@mangeltrueman was there - and their frogbit is tiny - they reckoned it was because they let it get buffeted a bit by the flow.
Cheers,
Simon